Photodetectors may be used to detect optical signals and convert the optical signals to electrical signals that may be further processed by another circuitry. Photodetectors may be used in consumer electronics products, image sensors, data communications, time-of-flight (TOF) ranging or imaging sensors, medical devices, and many other suitable applications. However, when photodetectors are applied to these applications in a single or array configuration, the leakage current, dark current, electrical/optical cross-talk, and power consumption can degrade performance.